Starting aids



April 28, 1970 C'URZON 3,508,328

- STARTING AIDS Filed June 14, 1968 'V'IE I Q 1 IO FIGL INVENTOR JKarnad6 m. B Y+Mw k w-7 ATTORNEYS United States Patent 3,508,328 STARTING AIDSThomas Curzon, London, England, assignor to C.A.V. Limited, London,England Filed June 14, 1968, Ser. No. 737,103

Claims priority, applicaginsizGreat Britain, July 3, 1967,

1/67 Int. Cl. H01f 7/06; Hb 3/00 US. or. 29 -611 2 Claims ABSTRACT OFTHE DISCLOSURE This invention relates to a method of assembly of part ofthe starting aid which is described and claimed in our co-pendingBritish application No. 43,-014/65.

The starting aid is of the kind having an electrically conductive memberextending with clearance within an end portion of a tubular member, andsurrounding the conductive member is a spirally Wound electric heatingelement which lies within or partially within the end portion of thetubular member, the heating element being electrically connected at itsopposite ends respectively to the members.

The object of the invention is to provide a method of assembly of theheating element in the end portion of the tubular member.

According to the invention, one end of the heating element is firstsecured to a thin walled tubular rod, secondly the tubular rod is placedover the conductive member and inside the tubular member, thirdly theheating element is wound upon the rod by rotating the rod, the heatingelement being drawn through a slot in the end portion of the tubularmember.

In the accompanying drawings:

FIGURE 1 is a sectional side elevation of the end portion of a partiallycompleted starting aid to which the method of the invention is to beapplied.

FIGURE 2 is a view showing the part of the starting aid omitted fromFIGURE 1 prior to assembly and FIGURE 3 is an end view of the completedaid.

Referring firstly to FIGURE 1 this drawing shows the end portion of astarting aid which in use, is exposed within the combustion chamber of acompression ignition internal combustion engine. There is providedanouter 3,508,328 Patented Apr. 28, 1970 tubular member 10 which isformed from metal and located in spaced relationship within the tubularmember is a conductive member 11. In order to support the conductivemember 11 within the tubular member, mineral insulation 12 is provided.In the present example the conductive member 11 is the end portion of aresistance element.

Within the annular space defined between the end of the tubular member10 and the mineral insulation 12 is a spirally Wound electric heatingelement which is formed from metal tape. The opposite ends of theheating element are electrically connected to the conductive member andthe tubular member respectively. An end view of the completed startingaid is seen in FIGURE 3 in which the heating element is referenced 13.

The tape as shown in FIGURE 2, is first attached by welding to the endof a thin walled tube 14, having a bore slightly larger than thediameter of the conductive member 11. The tube is then positioned overthe member 11 so that the tape lies within the tubular member and passesthrough a tangential slot 15 formed in the tubular member.

The tube 14 is then rotated thus drawing the tape into the annular spacebetween the tube and the tubular member at the same time the tape beingwound spirally about the tube. When sufiicient tape has been wound theouterend of the tape is welded to the tubular member 10 and the thinwalled tube 14 is welded to the conductive member 11.

If desired a portion of the element may be wound on the tube beforeinsertion into the tubular member the winding operation being completedas described.

Having described my invention what I claim as new and desire to secureby Letters Patent is:

1. A method of assembling the heating element in the end portion of thetubular member of the starting aid of the kind specified and comprisingfirst securing the heating element to a thin walled tubular rod,secondly placing the tubular rod over the conductive member and insidethe tubular member and thirdly winding the heating element upon the rodby rotating the rod, the heating element being drawn through a slot inthe end portion of the tubular member.

2. A method as claimed in claim 1 including the steps of securing therod to the conductive member and the element to the tubular member.

References Cited UNITED STATES PATENTS 2,157,050 5/1939 Bilger et a1296ll 2,936,358 5/1960 Heusser 296l1 WILLIAM I. BROOKS, Primary ExaminerUS. Cl. X.R.

